Me

you will earn 50 points if you answer it correct.

1. which of the combinations in the lab activity had indications that a chemical change occurred? defend your argument with evidence.

2. which of the combinations in the lab activity had indications that a physical change occurred? defend your argument with evidence.

3. are all physical changes reversible? explain your answer using an example you've observed in your everyday life.

4. give an example of something you've observed in your everyday life that is a chemical reaction. how did you know it was a chemical reaction?

Two things that biomedical has invented or innvated

Hot air balloons float in the air because of the difference in density between cold and hot air. in this problem, you will estimate the minimum temperature the gas inside the balloon needs to be, for it to take off. to do this, use the following variables and make these assumptions: the combined weight of the pilot basket together with that of the balloon fabric and other equipment is w. the volume of the hot air inside the balloon when it is inflated is v. the absolute temperature of the hot air at the bottom of the balloon is th (where th> tc). the absolute temperature of the cold air outside the balloon is tc and its density is ďc. the balloon is open at the bottom, so that the pressure inside and outside the balloon is the same. as always, treat air as an ideal gas. use g for the magnitude of the acceleration due to gravity.

What is a property of a double replacement reaction